This study uses income accumulated over ages 20–60 to examine whether richer or poorer individuals have more children. Income histories are calculated using yearly administrative register data from contemporary Sweden for cohorts born 1940–70. Differences by parity and income distribution are examined separately by sex. There is a strong positive gradient between accumulated disposable income (and to a lesser extent earnings) and fertility for men in all cohorts and a gradual transformation from a negative to a positive gradient for women. In particular, accumulated incomes are substantially lower for childless men and women than those with children. For men, fertility increases monotonically with increasing income, whereas for women much of the positive gradient results from low fertility among women with very low accumulated incomes in later cohorts. Most of the positive income–fertility gradient can be explained by the high incomes of men and women with two to four children.